This invention relates to a pneumatic lift device that has a simple and inexpensive construction, and, has a variety of common uses. In one preferred embodiment of this invention, the pneumatic lift device is sized and configured for use as an automobile trunk accessory. In another embodiment, the pneumatic lift device is configured as a stand-alone transport dolly. It is to be understood that the preferred embodiments in this specification are set forth for the purpose of aiding in the description and understanding of this invention. The embodiments are not intended to limit the scope of this invention or the variety of different applications to which the invented pneumatic lift device can be applied.
Air lift devices have been constructed in the past for a variety of different uses. Typically, an air lift is of a scissor-type pneumatic jack that is powered by an internal bellows inserted between a lift plate and a base plate. Piston-type air jacks have been used as automobile lifts and industrial elevator devices.
It is an object of this invention to avoid the scissors-type mechanism or the use of an air piston for raising and lowering a support platform. In the pneumatic lift device of this invention, a simple hinge mechanism is utilized to provide both a means of limiting the elevation of the support platform and a means of stabilizing the lift platform. In addition, an expandable air bladder is used that conforms to the underside surface of the lift platform. In this manner a substantial lifting force is developed with a minimum air supply pressure. In the embodiments disclosed in the specifications, the lift platform is substantially rectangular and when used as an automobile trunk accessory the lift device may be sized according to the compartment area of the trunk. When the pneumatic lift device is simply used as a common household lifting and transport device, the lift platform is preferably square and includes a square base with a carriage having four pivoting wheels.
Inflation of the internal bladder of the pneumatic lift device may be accomplished by a low pressure electric pump or by a simple foot-operated bellows pump. The low pressure electric pump may be conveniently powered by a cord that connects to the cigarette lighter of an automobile when the lift device is used as a trunk accessory, or by a rechargeable battery pack when the lift device is used in an environment without a convenient power source. Where the pneumatic lift device is a factory installed unit in the trunk of an automobile, the low pressure electric pump may be directly wired to the vehicle's wiring system.
It is to be understood that a primary object of the invented pneumatic lift device is to assist a person in lifting heavy objects into and out of an automobile or other vehicle. Additionally, it is an object of this invention to provide a household device to transport and lift objects to a moderate height. It is a further an object of this invention to construct the pneumatic lift device in such a manner that it is modular and may allow one or more lift units to be stacked to increase the elevation of the lifting the pneumatic lift device. These and other features of the invention will become apparent on a consideration of the detailed description.